Power Generation from Cheese Whey Treatment by Anaerobic Digestion and Microbial Fuel Cell

An important pollutant produced by the dairy industry during the cheese making process is cheese whey (CW) which is a liquid by-product with high content of organic matter. However, with an estimated worldwide production of 200 million tons per year and due to its high organic load, CW represents a huge opportunity for bioenergy production using bioprocesses. For this reason, the aim of this work was to determine the power generation from CW treatment using two coupled bioprocesses, anaerobic digestion (AD) and microbial fuel cell (MFC). In the first process the maximum methane production (MMP), methane production rate (MPR) and biochemical methane potential (BMP) were measured using an anaerobic batch bioreactor by 110 days of monitoring. Finally, the digestate generated from AD of CW was used in the second process to determine the polarization curve, voltage, power density, resistance and current. In the AD, the MMP, MPR and BMP were 813.26 mL, 46.2 mLCH(4)/L-bioreactor day and 338.9 mLCH(4)/gCOD, respectively. Also, the MFC generated a maximum voltage of 344 mV, power density of 59.6 mW/m(2), resistance of 486.72 Omega and current of 0.0003443 A. The integration of both processes produced a total energy of 12.275 kJ/gCOD with a total COD, TS and TVS removal of 88.6%, 56.6% and 80.4, respectively. These results show the great potential of cheese whey as a feedstock for bioenergy production, thereby developing a circular economy.